Overview of Congenital Heart Disease

Question 1

Congenital Heart Disease

Answer 1

• heart defect of formation or function present at birth
• incidence: 8/1000 live births
• second most common congenital defect to neurological

Question 2

Genetic Causes of CHD

Answer 2

• trisomy 21
• monosomies
• microdeletions
• single gene defects
• ~16% of CHD’s

Question 3

Environmental Causes of CHD

Answer 3

• alcohol consumption
• ix’s (eg. rubella)
• drugs (eg. retinoic acid)
• maternal diseases (eg. diabetes - insulin is an important growth factor for myocardium, lupus - baby is born with a very low heart rate)
• 2% of CHD’s

Question 4

Period when heart is starts forming

Answer 4

Weeks 4-8

Question 5

When does heartbeat start?

Answer 5

Day 28

Question 6

When are cardiac structures complete?

Answer 6

Weeks 7-8

Question 7

When are genetic and environmental factors most important?

Answer 7

Weeks 4-8

Question 8

Pathogenesis of the heart

Answer 8

-Due to an “injuring agent” that acts during a critical period to produce the abnormal development

Question 9

Simple Lesion

Answer 9

-one defect in heart, eg. patent ductus arteriosus

Question 10

Complex Defects

Answer 10

-multiple defects present, can sometimes make up a disease (eg. tetralogy of Fallot)

Question 11

Most common defect

Answer 11

Bicuspid aortic valve - 1%

Question 12

VSD

Answer 12

~32% of all CHD’s

Question 13

Which CHD’s make up ~8% of all CHD’s each?

Answer 13

• ASD
• PDA
• Pulmonary Stenosis
• Aortic Stenosis
• Tetralogy of Fallot

Question 14

Situs Inversus

Answer 14

-inversion of all organs in body

Question 15

Isomerism

Answer 15

-having two of the same. e.g. two LV’s

Question 16

Heterotaxy

Answer 16

-organs are distributed abnormally within body cavity

Question 17

Heart Failure

Answer 17

-clinical syndrome characterized by symptoms resulting from heart disease

Question 18

LV Failure

Answer 18

-when LV dysfunction results in fluid retention or exercise intolerance

Question 19

LV Dysfunction

Answer 19

-abnormality of contraction (systole) or relaxation (diastole)

Question 20

Pressure Equation

Answer 20

Pressure = Flow x Resistance

Question 21

Congestive Heart Failure

Answer 21

-produces fluid retention in soft tissues

Question 22

Heart Disease Symptoms

Answer 22

CHF can produce:

• dyspnea (alveolar edema)
• swelling in face/legs
• diaphoresis / fainting
• bloating in abdomen (ascites)
• poor feeding in young
• impaired exercise tolerance

Question 23

Heart Disease Signs

Answer 23

• fetus: hydrops (fetal fluid retention), stillbirth, growth retardation
• newborn: respiratory distress, poor feeding, cyanosis with R->L shunts
• adults: murmurs, cardiac enlargement, sudden death

Question 24

Two Types of CHF

Answer 24

• too much pulmonary blood flow

- reduced systemic flow

Question 25

Structural Defects that can produce too much pulmonary blood flow CHF

Answer 25

• patent ductus arteriosus
• atrioventricular septal defect
• VSD’s

Question 26

Structural Defect that can produce reduced systemic flow CHF

Answer 26

-obstructive left heart lesions

Question 27

Non-Structural Causes of CHF

Answer 27

• myocardial failure
• circulatory volume overload (eg. anemia)
• respiratory disease (severe)

Question 28

Cyanosis

Answer 28

• blue tinge to skin
• oxygen saturation 5 gm/L
• usually due to R->L shunts or lung disease

Question 29

Cyanotic Lesions

Answer 29

• TOF
• Total anomalous pulmonary venous return
• Transposition of the great arteries
• Tricuspid valve abnormalities
• Pulmonary atresia

Question 30

Investigation for Heart Disease

Answer 30

• Physical Exam/History
• Lab Values (CBC/Renal/Electrolytes)
• ECG
• Echo
• Radiography
• Catheter Hemodynamics

Question 31

History

Answer 31

• younger patients, focus on pregnancy, family history of CHD
• feeding/growth
• activity
• color
• breathing
• sleeping patterns
• fainting spells
• palpitations
• chest pain (rarely seen)
• exercise tolerance

Question 32

Physical Exam

Answer 32

• vitals including BP in four limbs
• work of breathing
• liver, lungs, soft tissue (congestion)
• cardiac activity/rhythm
• murmur timing and quality
• clubbing/cyanosis

Question 33

Indications for Fetal Electrocardiography

Answer 33

• abnormal 4 chamber view on outside scan
• family history
• significant exposure to alcohol/drugs
• positive amniocentesis for chromosomal abnormality
• other evidence of syndrome

Question 34

When are most CHD’s identified?

Answer 34

• at birth or shortly thereafter

- specific diagnosis made by more targeted investigations

Question 35

Prognosis of CHD

Answer 35

-most can be treated if not cured